Call-charging telephone-exchange system



Dec. 25, 1928.

' A. E. HAGUE CALL cmmeme TELEPHONE EXCHANGE SYSTEM Filed Oct. 26, 19277 Sheets-Sheet 1 -1 P I H /NVEN ran ALF/1'50 5 H4005 BY Q6, M

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I A. E. HAGUE CALL CHARGING TELEPHONE EXCHANGE SYSTEI Filed Oct. 26192'! 7 shgatksheet 2 //vv/v TOR AL FRED L. HAGUE BY 6. aw

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A. E. HAGUE CALL CHARGING TELEPHONE EXCHANGE SYSTEI /NVENTOfi-' ALF/?ED[HAGUE Arron/vs) I A. E. HAGUE CALL CHARGING TELEPHONE EXCHANGE SYSTEMFiled Oct. 26, 1927 7 Sheets-Sheet 4 Dec. 25,1928.

A. E. HAGUE CALL CHARGING TELEPHONE EXCHANGE SYSTEM Filed Oct. 26, 1927tS-Sheet 5 /NVENTOR ALFRED t. luau: By '6 (7:24-

ATTOHVEY Dec. 25,1928. 1,696,271

. A. E. HAGUE cm. err/meme TELEPHONE Exommus sxs'mm Filed Oct. 26, 1927'7 sheets-shet 6 Arm/wry 1 7 7 2 u 6 e 9 n S h. 1 t 8 9 h M S E w T S Ys E G M. H 7 C 2 E x m U E G E 6 N A 2 H P 1 m w E w d e A G 1 m n G n HIn- C kfiqkmk Ill U m Ill UPI} A C III U) MQFR Ill U) ll U) LU H. II UIll LU ll U): II Ill 13 Dec. 25; 1928.

Patented Dec. 25, 1928.

UNITED STATES PATENT OFFICE.

ALFRED E. HAGUE, OF WEST ORANGE, NEW JERSEY, ASSIGNOR TO BELL TELEPHONELABORATORIES; INCORPORATED, OE NEAV YORK, N. Y., A CORPORATION OF NEWYORK.

CALL-CHARGING TELEPHONE-EXCHANGE SYSTEM;

Application filed October 26, 1927. Serial No; 228,715.

This invention relates to a telephone ex change system and moreparticularly to a systemin which a charge is automatically made for acompleted call; The object of theinvention is the provision of means forcon trolling the call charging which will charge the calling subscriberin such a manner as to more equitably recompense the operating telephonecompany for the use of exchange equipment.

In large exchange areas having several offices some of which may. belocated at vary distant points in the area, it is desirable that meansbe provided whereby a calling subscriber may be charged differently forcalls to oflices which are most remotely located from theofiice in whichthe calling line terminates, than for calls toofiices which are not soremotely located, since remotely located otiicosmust be reached overlong interofiice trunks which are expensive to install and maintain andit is not equitableto the company to provide service to all points inthe exchange area at the same basic-rate.

Of course, where calls are handled on a manual basis the rate of chargemay be very easily cared for by the operator, who is able to require thecalling subscriber'to deposit the required number of coins in his coinbox before giving him a desired connection or to cause the properoperation of the subscribers message register. However, whereconnections are established entirely by machine switching means someprovision must be made for automatically controlling the charging of thecall in accordance with the zone of the exchange into which the call hasbeen extended by the calling subscriber.

Furthermore, it is not equitable to the operating telephone company thatfor a basic charge the sul'iscriber shall be enabled to hold anestablished connection indefinitely. In manual systems, of course, theoperator is able to assess the charge in accordance with the number ofunit periods during which conversation is continued on any call. Where,however, calls are extended by means of a machine switching device,operator'supervision is not desirable and from a standpoint of economythe supervision of elapsed time should be attained by automatic means.Both automatic charging in accordance with the zone of the exchange areainto which that which would be proper for a single unit charge, forexample. five, minutes. The timing switch, during the intial portion ofits cycle, transmits impulses to the calling subscribers messageregister, the number of register operations depending upon the Zone ofexchange into which the calling subscriberhas dialed. The timing switchcontinues to advance through successive cycles as long as theconversation lasts, transmitting regis tering impulses during eachcycle. The number of registering impulses which the timing switch sendsfor each unit period is controlled by the sequence switch of thedistrict selector with which the charge controlling equipment isassociated and by the sender, the sequence switch assuming differentpositions dependent on the zone into which the call is extended by thedistrict selector. Upon the termination of the call the timing switch isarrested as soon as it again reaches normal and the connection isdismissed. Registration is thus effected during the conversation inaccordance with the elapsed time for the conversation and in accordancewith the zone of the exchange into which the call was ex tended.

A clearer conception of the scope and purpose of the invention will beobtained from a consideration of the following description in connectionwith the attached drawings in which:

Fig. 1 shows a calling subscribers line together with certain relays forpreventing interference between calling lines;

Fig. 2 shows a start circuit and a portion of two link circuits;

Fig. 3 shows a line selector;

Fig. 4 shows a link circuit for associating the sender with the districtselector;

finder i and district Fig. 5 shows a portion of a register sender;

Fig. (5 shows a message register controlling circuit. associated withthe district selector of Fig.

Fig. 7 shows in schematic form selectors for completing a connection toan automatic subscriber, to a manual ofiice or to an operator; and

Fig. 8 shows the manner in which Figs. 1 to (5 should be arranged.

The invention has been embodied in a disclosure which is substantiallylike that of U. S. Patent 1,567,072 to W. H. Matthies, granted December29, 1925. Both the present disclosure and that of the Matthies patentshow a skeletonizcd sender substantially the same as that disclosed inthe more complete disclosure of U. S. Patent 1,589,402, granted to O. H.Kopp, June 22, 1926, and reference to the Kopp patent is ma do foroperations not completely described herein.

As in the case of the above mentioned patents a plurality of linkcircuits are arranged to serve a group of ralling lines and are takeninto service in rotation. lVhen a link circuit completes its function ithunts for and associates itself with a district selector which is readyfor use and the link and district remain in a sub-allotted conditionuntil the next link in the series has been put into service. The linkcircuit is then put into an allotted condition from which it will beadvanced by the initiation of a call and the action of the start circuitof Fig. 2. The trip circuit of Fig. 1 and start circuit of Fig. 2 are soarranged that only one line may be served at a time and so that theremaybe cooperation between two groups of lines to each of which a groupof link circuits is individual. The details of these functions aredescribed in the above mentioned Matthies patent and, since they form nopart of the present invention, will be omitted from the followingdescription.

It will be assumed that the subscriber at sub-station first initiates acall for which he is to be charged three times for each five minutes ofconversation. Vhen the subscriber at substation 100 removes his receiverfrom the switchhook a circuit is closed from battery, through thewinding of line relay 101, inner back contact of relay 102. over thesubscribers line to ground at the outer contact of relay 102. Relay 101in operating closes a circuit from battery through resist ance 104,winding of relay 103 to ground at the outer front contact of relay 101.It also prepares a circuit from battery through resistance 111 and theleft winding of relay 109 in parallel, inner front contact of relay 101to conductor 114, to identify the calling line to the line finder. Relay103 in operating closes a circuit from battery over the back contact ofrelay 201, conductor 130, right winding of relav 108, inner back'contactof relay 107, inner right contact of relay 10, to ground at the leftcontact of relay 109.

Relay 10S operates in this circuit and closes a locking circuit foritself from battery through the right winding of relay 201, conductor129, over back contacts of relays similar to relay 108, individual toother groups of lines appearing before the same line finder, inner leftfront contact and left winding of relay 108 to ground at the rightcontact of relay 109. Relay 10S prepares a circuit from ground at itsouter right front contact through the winding of trip magnet 303 of theline finder to battery in preparation for tri )ping the proper set ofbrushes when the line finder is operated. Relay 201 operates in thelocking circuit of relay 108 and in combination therewith closes acircuit from ground, over its outer right contact, conductor 1.28. innerright contact of relay 108, winding of relay 110 to battery. Relay 110locks over its inner right contact to ground at the left back contact ofrelay 109. Relay 110 closes a circuit for starting the allotted linefinder.

Assuming that the link and line finders shown are the ones to be usednext, sequence switch 400 will be standing in position 1 and sequenceswitch 300 in position 2. The operation of relay 110 will thereforeclose a circuit from ground at its outer right contact, outer left frontcontact of relay 108, inner left front contact of relay 103, conductor131, left back contact of relay 202, inner left back contact of relay203, conductor 206, upper left and lower right contacts of cam 103,brush 402 and terminal 401, conductor 3T8, upper right and lower leftcontacts of cam 301, winding of relay 302, to battery.

Relay 302 in operating closes a circuit from battery through the windingof up-drive magnet 304; of the line finder, comluctor 007, brush 603 andnormal terminal of timing switch 000, conductor 608, right front contactof relay 302, lower right contact of cam 301, outer left front contactof relay 302, conductor 009, normal terminal and brush 002, interruptercontacts of stepping magnet- 62:"), conductor (310 to ground at thelower left contact of cam 336. The line finder moves upward under thecontrol of magnet 301 and, since trip magnet 303 is operated, the properset of brushes is tripped. As soon as the line finder moves upward. alocking circuit is provided for relay 302 extending over its inner leftfront contact, upper contacts of cam 308, right back contact 0 1' relay320, commutator strip 321, brush 322 to ground, which holds relay 302operated independent of the start circuit. As soon as commutator brush307 engages segment 305, a circuit is closed from ground over brush 307and segment 30:), lower right and upper left contacts of 'am 306,conductor 101, contact 230 of key 20 1-, inner right front contact ofrelay 201 to conductor 129 and the right, winding of relay Inc 201. Thiscircuit slnlnts the winding of re lay 108 and causes that relay torelease, in turn releasing the trip magnet 303. When brush 307 leavessegment 305, the circuit of relay 201 is opened and that relay alsoreleases. When line finder brush 381 makes contact with terminal 380which is connected to conductor 114 and therefore to battery, a circuitis completed from this battery through the winding of relay 320, lowerleft and upper right contacts of cam 341, to ground at the lower rightcontact of cam 339. Relay 320 operates in this circuit and closes ashunt around its winding through resistance 31.9, to ground overcommutator strip 321 and brush 322. This reduces the resistance inseries with the winding of marginal relay 109 suflicie-ntly to causethat relay to operate and open the locking circuit of relay 110, whichin turn opens the energizing circuit of relay 302. The operation ofrelay 320 also opens the locking circuit of relay 302, causing thatrelay to release. The release of relay 302 closes a circuit from groundthrough the winding of cut--ofi' relay 102, conductor 112, terminal 327,brush 326, back contact of relay 317, right back contact of relay 302,lower right contact of cam 324, resistance 323 to battery. The operationof cut-off relay 102 opensthe circuit of line re lay 101, removingbattery from conductor 114, releasing relays 109 and 320.

At the time relay 302 operated, it closed a circuit from ground at the,lower left contact of cam 336, conductor 610, contacts of mag net 625,brush 602, conductor 609, outer left front contact of relay 302, lowerright contact of cam 311, conductor 379, terminal 407 and brush 406 ofthe link district finder 410, lower right contact of cam 408, winding ofrelay 409, resistance 411 to battery. 7 Relay 409 operates and closes a.circuit frombattery through the winding of sequence switch magnet 400,upper contact of cam 412, to ground at the outer left front contact ofrelay 409, advancing the link sequence switch 400 to position 2. hensequence switch 400 leaves position 1, relay 409 is released. Inposition 2, a circuit is closed from battery through the winding ofrelay 413, upper contacts of cam 414, right backcontact of relay 415, toground at the left contact of cam 416. Belay 413 operates, closing acircuit from battery through the left winding of relay 417, left frontcontact of relay 413, to ground at the left back contact of relay 415.Relay 417, in operating, closes a circuit from battery through thewinding of up-drive magnet 418 of the-sender finder 420, left contact ofcam 479, outer right contact of relay 417, to ground at the left backcontact of relay 409. The sender finder moves upward under the controlof magnet 418 in search of an idle sender.

. Relay 413 also closes a circuit from battery upper left contacts ofcam 421,'middle windiig of relay 415, to ground at the right contact ofrelay 413. An idle sender is characterized by battery connected toconductor 502. Then, therefore, brush 422, engages terminal 423,corresponding to the sender of Fig. 5 which is assumed to be idle, thetest circuit above traced is con'lpleted over terminal 423 to batteryand relay 415 operates quickly. The relay 415 in operating closes alocking circuit for itself from battery through the right winding ofrelay 415, upper contacts of cam 421, to ground at the left frontcontact of relay 415. It also opens the circuit of relay 417- whichreleases, to in turn release magnet 418 and bring the sender finder torest on the idle sender. The release of relay 417 in turn releases relay413. With relay 413 released and relay 415 operated, a circuit is closedfrom battery through the winding of sequence switchmagnet 400,lower leftcontact of cam 476, contact 427 of jack 428, left back contact of relay413, right front contact of relay 415 to ground at the left contact ofcam 416, advancing sequence switch 400 to position 3.

lVhcn sequence switch 400 reaches position 3 a circuit is closed fromground through the left and middle windings of relay 503, back contactsof relays 504 and 505, conductor 506, terminal 430, brush 431, rightcontact of cam 434, brush 432 and'terminal 433, conductor 315, contactsof cam 316 (assuming that the district selector has been advanced toposition 3 as hereinafter described) through the left winding of relay317 and the winding of relay 351 in parallel-to battery. Relay 317marginal and does not operate. Relay 351 operates but is ineffective atthis time. Relay 503 also 01:30.13008311Cl closes an obvious circuit forrelay 507, which in turn. closes a circuit for relay 509. Relay 509closes a circuit for relay 510. I

As soon seruicncc switch 400 arrived in position 2% it prepared thepulsing circuit for receiving dial pulses. This circuit may be tracedfrom battery through the left winding of relay 500, conductor 537,terminal 440, brush 4.41, lower contact of cum 429, brush 473, terminal477, conductor left contact of cam 335, left back contact of relay 317,brush 334, terminal 333, conductor 117 through the subscriberssubstation, conductor 116, terminal 332, brush 331, right back contactof rclay 317, winding of relay 330, left contact of cam 329, conductor382, terminal 442, brush 443, upper right and lower left contacts of cam403, brush 444 and terminal 445 to ground at the back contact of relay513. Relay 500 operates, in turn operating relay 518 in the well knownmanner, relay 518 in turn operating relay 519. A circuit is thereuponclosed from the source of tone current 516 through the right winding ofrelay 500, register steering switch 520 in its normal position, irontcontact of relay 510. lower contact of cum 514 to ground at the frontcontact of relay 509. This tone is transmitted to the calling subscribedto inform him that the sender is ready to receive impulses which he maythen send out by manipulating his dial.

When relay 510 operated it removed battery from conductor 502, releasingrelay 415. With relay 415 released, a circuit is closed from batterythrough the winding of quence switch magnet 400, upper left contact ofcam 476, right back contact of relay 415 to ground at the lower leftcontact of cam 416. Sequence switch 400 advances to position 5 over thiscircuit and remains in this position throughout the further operation ofthe sender.

The calling subscriber now proceeds to dial the desired line number forsetting the registers and translator (not shown) of the sender in thewell known manner. After the dialing of the first digit the registersteering switch, one wiper of which is shown at 520, advances fromnormal, closing a circuit for relay 517, extending from battery throughthe winding of relay 517, terminals and brush 520, contacts of relay519, contact 0t cam 514 to ground at the outer right contact of relay509. Relay 5'17 closes an obvious circuit for relay 521.

As soon as the code registersoi the sender have been set in accordancewith the first two digits dialed by the calling subscriber, thetranslator is set in the manner described in the aforementioned patentto O. H. Kopp. lVhen the translator assumes its setting relay 533operates, closing a circuit over the translator are 534 through a backcontact of relay 535, if the subscriber has dialed the number of asubscriber located in a zone 01 the exchange for which an additionalcharge must be made on the calling subscribers message register, thencethrough the winding of relay 530 to battery. Relay 536 energizes andlocks orer its left front. contact, the contact of cam 514 to ground atthe outer right front contact of relay and extends locking, groundthrough its left front contact to the winding of relay 538. causing theoperation of the latter relay. Relay 538 upon operating establishes acircuit from ground at the outer right contact of relay 509, the contactof cum 514, the contact of relay 538 to battery through the winding ofrelay 5a.). Relay 535 operates, opening the initial energizing circuitof relay 536 and connecting the translator are 534 over the cable 530 tothe class switch 540 which is diagrammatically indicated in the upperright portion of Fig. 5. The class switch is thereupon set from the are534 of the translator. ltelay 536 upon energizing prepares a circuitextending from ground over its right contact, the contacts of cams 541and 542 being closed during the brush selection controlling positions ofthe sequence switches associated with the sender, conductor 543,terminal 439, brush 438, right contacts of cam 405, brush 406, terminal407. conductor 379, to the lower left contact of can] 399. This circuitis completed as will be described hereinafter through the winding ofrelay 611 of the registration controlling circuit for indicatin at theregistration controlling circuit the fact that the SIIiIJSClibGl' hasinitiated the establishment of a connection into a zone of the exchangearea for which he should be assessed an additional charge.

\Vhcn the link circuit advances into posi tion 2 for hunting for an idlesender, a circuit is closed for relay 314, extending from batterythrough the left winding of relay $314, lower right contact of cam 313,lower right contact of earn 312, conductor 375, terminal 477, and brush478 of district finder 410 to ground at the right contact of cam lVhenrelay 302 releases and relay 314 energizes, a circuit is closed foradvancing sequence switch 300 into position 23, extending-from batterythrough magnet 300. the upper left contact of cam 3:28, the right frontcontact of relay 314, the left back contact of relay 302, conductor($09, brush 002, interrupter contacts of magnet 025, conductor (310 toground at the lower left contact of cum 330. As the sequence switch 300advances from position 2 to 3, relay 314 releases.

\Vith sequence switch 300 in position 3 relay 314 is again energizedover a circuit extending from battery through its left winding, thelower right contact of: cam 313, the upper left contact of cam 312.conductor 378, terminal 401 and brush 402 of district finder 410, thelower right and upper left contacts of ca1n435,brush 450 and terminal437 oi sender tinder 420, the trout contact of relay 521, the ba ckcontact of relay 504, the left contact oi cam 520, winding of senderstepping relay 522. winding oi overflow relay 523. left contact of cam527. resistance 530 to ground. Relays 522 and 314 operate in thiscircuit, relay I314 locking over its outer left front contact and thelower left contact of cam $313. thence over the circuit traced, wherebyit remains energized as the sequence switch 300 ad 'ances into position4. Relay 314 also closes a circuit to advance sequence switch 300 intoposition 4, extending from battery through magnet 300, upper leftcontact of cam 328, right front contact of relay 314, thence aspreviously traced to ground at the upper left contact of cam 336.

Vhen the district sequence switch reaches position 4 for controllingbrush selection, the circuit previously traced from the contact of relay436 and extending to the lower left contact of cam 399 is extended overthe left contacts of cam 399, conductor 612, patched to conductor 612,to battery through the right winding of relay 611. Relay 611 uponenergizing locks over its left winding and left front cont-act,conductor 613, patched to conductor 613 to ground at the upper leftcontact of cam 336.

The district selector is now controlled by the sender in its brush andgroup selections and then proceeds to hunt for an idle trunk in the wellknown manner. After an idle trunk is selected, a circuit is establishedin position 9 of the sequence switch 300 for relay 314, extendingfrombattery through the right winding of this relay, the lower left contactof relay 352, the front contact of relay 351, the lower contacts of cam308, com mutator segment 397, brush 398, advancing the sequence switch300 into position 10. In position 10 relay 314 remains energized overthe circuit just traced. In position 10 which is the selection beyondposition of the district circuit the control of succeeding switches iseffected over a fundamental circuit which may be traced in part frombrush 389, through the lower right and upper left contacts of cam 358,the right back contact of charging relay 396, conductor 378, thence astraced to the sender through the windings of relays 522 and 523, cam546, brush 544, compensating resistance 545, left back contact of relay524, right front contact of relay 507, conductor 543, returning overterminal 439 and brush 438, the right contacts of cam 405, brush 406,and terminal 407, conductor 37 9, the right contacts of cam 395, tobrush 388.

As soon as selections are completed and the connection has been set upto the called sub-- scribers line, reversed battery from the incomingselector operates relays 522 and 523 in the usual manner. These relaysin turn cause the operation of relay 531 and relays 524 and 504. "Withthese relays operated, the sender is advanced to position 18 forcontrolling talking selection. Relay 351 is operated in parallel withthe winding of relay 317 throughout selections. The operation of relay504 above mentioned now opens a shunt around the right winding of relay503, including that winding in the circuit of relays 351 and 317. Relay351 thereupon releases, in turn opening the circuit of relay 314, whichalso releases. Upon the release of relay 314 the district sequenceswitch 300 is advanced into position 11 over a circuit extending frombattery, winding of magnet 300, right contacts of cam 342,1ight backcontact of relay 314, outer left back contact of relay 302 to ground astraced at the lower left contact of cam 336. .As the sequence switchenters position 11, ground is connected to conductor 315 at the upperright contact of cam 336, which is extended over terminal 433, brush432, upper contacts of cam 446, left winding of relay 415, right backcontact of relay 409, left contact of cam 434, brush 431, terminal 430,conductor 506, left back contact of relay 505 to the wind ings of relaySince these windings are also connected to ground, relay 503 now-rcleases, in turn releasing relay 507. The release of relay 507. doesnot release relay 509, since that relay is locked to its own frontcontact.

A circuit is therefore closed from ground over the left back contact ofrelay 507, front contact of relay 509 to the winding of relay 505, whichrelay locks over its middle left contact to conductor 506 and to groundas above traced. After leaving position 10, relays 351 and 31.7 are bothdisconnected from conductor 315. Sequence switch 300 is then advancedinto position 12 over a circuit extending from battery through magnet300, the upper left contact of cam 328, the upper contacts of cam 341,to ground at the right contact of cam 339. In passing into position 12the subscribers linebecomesdisconnected from the sender at contacts ofcams 329 and 335.

Vith sequence switch 300 in position 12, relay 314 is energized in acircuit extending to the sender from battery through its left winding,the lower right contact of cam 313, the upper left contact of cam 312,conductor 378, terminal 401, brush 402, the lower right and upper leftcontacts of earn 435, brush 436, terminal 437, conductor 532, the frontcontact of relay 521, the front contact of relay 504, the right contactof cam 526, the sender sequence switch being in position 18 for talkingselection, the windings of relays 522 and 523, the right contact of cam527 to ground through resistance 530. Relays 314 and 522 energize inthis circuit. relay 314 closing a circuit extending from battery throughsequence switch magnet 300, the upper left contact of cam 328, g

the outer right front contact of relay 314, the lower left contact ofcam 394 to ground at the upper right contact of cam 350. Relay 314 uponenergizing locks to the fundamental. circuit over its left winding andouter left front contact and lower left contactof cam 313. As sequenceswitch 300 rotates out of position 12 toward position 16 ground isintermittently connected to the fundamental circuit in shunt of senderstepping relay 522 at the lower left contact of cam 350. lVhen thesender is satisfied as to its talking selection setting, the fundamentalcircuit is opened at the sender through the operation of relay 525,and'relay 314 deenergizes, arresting sequence switch 300 in its nextstopping position. The sequence switch may be arrested in any one ofthree positions; position 13 which may be a no-charge position. position14 which is a charging position for connections to certain zones of theexchange, and position 15 for connections to an operators position.

At the sender after talking selection is completed, relay 515 operatesconnecting battery to conductor 506 in parallel with the winding ofrelay 505. The currentin this circuit is now suiiicient to operate relay415 which closes a circuit from battery through the left winding ofrelay 417, left contacts of cam 421, to ground at the left front contactof relay 415. Relay 417 closes a circuit from battery through thewinding of sequence switch magnet 400, upper contact of cum 479, outerright front contact of relay 417, left back contact of relay 409 toground, advancing sequence switch 400 to position 6. In this position,all of the conductors extending to the sender are opened and the senderis completely released. As soon as quence switch 400 leaves position 5,relay 415 releases and in turn releases relay 417 unless the senderfinder 420 is standing on one of its top ten terminals. If the latter istrue, relay 417 is held operated in a circuit from battery over its leftwinding, left front contact, upper left contact of cam 424, con'nnutator segment 464, brush 463 to ground. Vith relay 417 operated at thistime, a circuit is closed from battery through resistance 411, windingof relay 409, lower contacts of cam 414, inner right front contact ofrelay 417, lower left contact of cam 416 to ground. Relay 409 locksthrough its inner left contacts to ground at the lower contact of earn467 and also closes a second locking circuit for relay 417. lVith relay409 operated, a circuit is closed from battery through the winding ofdown-drive magnet 465 of the sender tinder 420, leftcontact of cam 41:2.to ground at the outer left front contact of relay 409. \Vhen the senderfinder reaches its lowermost position, a circuit is closed from groundover brush 463, bottom ecnnn'iutator segment 406, upper contact of cum456 to resistance 411, shunting the winding, of relay 409 and causingthat relay to release and in turn release relay 417. With relay 417released in position 6, a circuit is closed from battery through thewinding of sequence switch magnet 400, lower right contact of cam 476,right back contact of relay 417. to ground at the lower left contact ofcam 416, advancing sequence switch 400 to position 7.

\Vhen sequence. switch 400 reaches position 7, the link circuit is readyto associate itself with another district. If another district isstanding in position 1 waiting association with a link, a circuit willbe closed from ground over the lower left contact of cam 3390f thatdistrict, contact 393 of ack 374 conductor 392, contact of jack 448,contact of jack 449, upper contact of cam 410. right back contact ofrelay 415, upper contacts of cam 414, winding of relay 413 to battery.Relay 413 closes a circuit from battery through the left winding ofrelay 417, left front contact of relay 413, to ground at the left backcontact of relay 415. Relay 417, in operating, closes a circuit forup'drive magnet 447 of the district lindcr 410, lower right contact ofcam 479, right front contact of relay 417, left back contact of relay409, to ground. The district tinder moves upward under control of magnet447 in search of the district which is awaiting a link. Such a districtis identified by battery connected over the left contacts of cum 2544 ofthat district, contact 37.) oF jack 37-11, to conductor 300. lclay 41 inoperating. closes the Sfllllt? circuit through the right and middlewindings of relay 415 as it closed in posit-ion 2. At this time the testcircuit extends from ground at the right front contact of relay 413,through the middle winding of relay 415, upper left and lower rightcontacts of cum 421, left winding of relay 415, right back contact ofrelay 400, lower right and upper left contacts of cam 419, contact ofjack 449 to brush 451.

If the district for which the district finder is hunting does not liebetween the last position occupied by the finder and the top of itsbank, it will continue to move upward until brush 45b engages segn'ient45'2, completing a circuit over the upper right contact of cam 408,winding of relay 409, resistance 411 to battery. The operation of relay409 opens the test circuit, opens the circuit of upalrivc magnet 447 andcloses a circuit from battery through the winding of down-drive magnet454, lower right contact of cam 412. left front contact of relay 409 toground. The district finder is restored to its lowermost position underthe control of magnet 454. at which timeacircuitisclosed from groundover brush 453, bottom segment 455 of the district finder commutator,lower right contact of ram 450 to resistance 411, shunting and releasingrelay 409 which restores the test circuit and the circuit of up'driremagnet- 447. \l'hen brush 451 encounters terminal 450 to which conductor360 extends. the test circuit is completed and relay 415 operatesquickly as in the previous case. Relay 415 locks through its rightwinding. the upper contacts of cam 421, to ground at its left frontcontact. opening the circuit of relay 417 to deeuergize magnet 447 andbring the district tinder to rest on the terminals of the district.iVitli relay 415 opcrated and relay 417 released. a circuit is closedfrom battery through the winding of sequence switch magnet 400. lowerleft contact of cum 470. contact 427 of jack 428. back contact of relay413. right front contact of relay 415, upper right contact of Elm cam416, contacts of jacks 449 and as to conductor 392. Sequence switch 4:00advances to position 8 in this circuit.

Relay 415 is held operated in position 8 from battery at the districtover terminal 150, brush 151, contact of jack &9, upper left and lowerright contacts of earn 119, back contact of relay e109, left winding ofrelay 415, lower right and upper left contacts of cam 421, to ground atthe left front contact of relay 415. lVith relay 115 operated, a circuitis closed from ground at the left contact of cam 116, right frontcontact of relay ll-5, upper left contact of corn +1529, brush 478,terminal 477, condiiictor 375, lower right cont-act of cani 312, lowerri" t contact of cum 313, left winding of rcaiy 31 t to battery. Relay314i operates and closes a circuit froi'n. battery through. the windingof sequence switch 300, upper left contact of earn 328, right frontcontact of relay 31 i, outer left back contact of relay 302, thence astraced to ground at the lower left contact of can] 336. Sequence switch300 advances to position 2 in this circuit, releasing relay 314. Theadvance to position 2 removes ground from conductor 392 and battery fromconductor 366. The removal of battery from conductor 366 opens thecircuit of relay 115, and that relay releases, closing a circuit frombattery througl'i the winding of sequence switch magnet 400, upper leftcontact of earn 47 6, right back contact of relay 4:15, to ground at thelower left contact of earn 116. Bequence switch 400 advances to position9.

The link circuit remains in this position until the link circuitstanding next to it in the series is advanced from position 1 for thepurpose of selecting a sender. Link circuit 260 occupying that relationhip to the link circuit of'F 4%, a circuit may he traced from groundover the lower contact of cain 261, upper right contact of earn 262,conductor 263, contact 460 of jack 4-28, upper right contacts of cams4:61 and 462, winding of quence switch magnet 100 to battery, advancingthe link circuit to position 10 which is the equivalent of position 1,so that the link circuit is ready to operate in response to the nextcall in the group of lines served thereby.

As soon as the sequence switch 300 advances into the talking position acircuit is established for supplying the callingsubscriber with talkingcurrent, which circuit may be traced from battery, through the lowerleft winding of repeating coil 360, upper right contact of cain32$),windins; of relay 330, right back contact of relay 317, brush 331and terminal 332, conductor 116, over the subscribers line, conductor117, terminal 333 and brush 334i, outer left back contact of relay 317,lower contactof cum to ground, through the upper left winding of coil360. Relay 330 energizes in this circuit closing a circuit for relay 351extending from battery, winding of relay 351, resistance 390,

contact of relay 330 to ground over the upperv contacts of cain 350.Relay 350 energizes but of the exchange requiring three operations ofthe message register 105 for each unit period of conversation, F or thiscall therefore the district sequence switch 300 has been setintoposition 1a. lVith sequence switch 300 in position 14:, when thecalled subscriber l'QElJOBClS a circuit is completed for relay 361extending from the tip brush 389, over the lower contacts of cum 358,upper right winding of repeating coil 360, winding of relay 361, lowerright winding; of coil 360, upper contacts of can't 395 to brush 388.Relay 361 energizes and a circuit is established for relay 302 as soonas interrupter 387 closes its lower contact, from battery, winding ofrelay 302, lower Contact of interrupter 387, lower left and upper rightcontacts of earn 390, front contact of relay 361, upper contact of cum3% to ground at the upper right contact of cum Upon the energization ofrelay 302 a circuit is closed to advance the timing switch 600 oifnormalas soon as the interrupter 387 closes its upper contact, whichcircuit may be traced from battery, winding of stepping magnet 625,brush 601 and its normal 'tcrn'iinal, conductor-614e, upper rightcontact of cam 364, outer left front contact of relay 302, upper contactof inter rupter 387, to ground as traced at the upper right contactofearn 350. When the inter-- rupter 387 breaks its upper contact, magnet625 deencrgizes advancing switch 600 into position 2. V

V/ ith switch 600 in position 2 a circuit is closed for operating thecharging relay 306 extending from battery, winding of relay 396,conductor 615, brush 1 in position conductor 631, thence as tracedthrough the front content of relay 361 to ground at the upper rightcontact of earn 350. Relay 396 upon energizing locks overits inner leftfront contact. the lower left contact of cam 394: to ground at the upperright contact of 33111 350. A circuit is now closed for opeii ating thesu hscribefs inessag'e register 105 extending; from ground. winding ofregister 105, back contact of cutoff relay 101, conductor 11s terminal380, brush 381. conductor 616 patched to conductor 616, conductor 617patched to conductor 617, lower-left and upper right 001 acts of cam308, conductor 616 patched through conductor 619 to conductor 619, brush606, in position 2, conductor 620, inner left front contact of relay 396to battery, through reistance 386.

After an interval more than suflicient to en- Ion able the operation ofmessage register 10:), the interrupter 387 upon again closing its uppercontact, advances the timing switch 600 into position, 8 over the samecircuit which advanced it into position 2. From po sition 2 the timingswitch is advanced rapidly by the interrupter 391, through positions 3to 6 inclusive over a circuit extending from battery, winding of magnetG25, brush (501 and strapped terminals 3 to 6, inclusive, of its bank,conductor 621 to ground through contacts of interrupter 391. As brush($00 passes through position a. the message register is again ope 'atedover a circuit extending from its winding to conductor (310, thence overconductor (316' patched thereto, the outer lett contact of relay 611,conductor 622 patched to conductor (322, the No. 1 terminal associatedwith brush 600, thence as traced to battery. Again as brush 600 passesthrough position 6, the message register 105 is operated for the thirdtime over the circuit previously traced to the outer left front contactof relay G11, thence over conductor 623 patched to conductor 623, theNo. (3 terminal associated with brush (506, thence to battery. Threeoperations of the message register 105 are thus eiiected before thetiming switch reaches position 7.

From position 7 the timing switch 000 is advanced by the slow timinginterrupter 62-l into its normal position, over a circuit eX- tendingfrom battery, winding of stepping magnet 625, brush 601 and strappedterminals 7 to 22, inclusive, associated therewith, conductor 626patched through conductor 626 to conductor 627, contacts of interrupter624, conductor 028, right front contact of relay 302, conductor 608, toground over the brush 603. Interrupter 62l is designed to close at longintervals so that the entire time for a revolution of timing switch 600to be completed will require approximately five minutes. When the switch(300 reaches normal it is again advanced into position 2 as previouslydescribed where overtime registration begins. From this position theswitch advances in a second revolution again operating the messageregister 105 as it passes through positions 2, 4 and (i. This cycle ofoperations is thus repeated every live minutes during the conversationand the register is operated three times during each cycle or each unitperiod of conversation.

iVhcn the calling subscriber hangs up to terminate the call, relay 330deenergizcs in turn opening the circuit of relay 351. A circuit is nowcstablished for relay 317 extending from battery, through its leftwinding, the lower left and upper right contacts of cam 316, the backcontact of relay 351 to ground at contacts of interrupter 391. Relay317, upon energizing, locks over its right winding, innermost rightfront contact to ground at the upper left contact of cam 336,

disconnects the calling line from the left windings of repeating coil360 at its back contacts, and closes a circuit for advancing thesequence switch 300 into position 17, if at the time the timing switchis in position 1. or 2. This circuit may be traced from battery, windingof magnet 300, lower right and upper lcl't contacts of cum 301,conductor 6'29, brush ($05 in position 1 or 2, conductor (330. frontcontact of relay 317, thence to ground at the upper left contact of cam336. It the timing switch is in positions 7 to at the time relay 317energizes, the timing switch is immediately buzzed into normal posit ionover a. circuit extending from battery, through the winding of magnet($25. brush (302 and strapped terminals of its bank, llllfll'llllll'tl'contacts of magnet 025, strapped terminals 7 to associated with brush605, brush (50.7, conductor (52-50, contacts of relay 3 17 to groundattheuppcrlettcontactofcam336. Assoonas the timing switch reaches normalthe circuit above traced for advancingsequenceswitcli PM is closed andthe stepping circuit of magnet (S25 is opened. It disconnection isinitiated at the time the timing switch is advancing through positions 3to (S, the sequence switch 300 is not advanced into position 17 untilthe timing switch reaches position 7 and the advance of the timingswitch through positions 3 to 6 being directly under the control ofinterrupter 391, the operation of the subscribers register in positions4 and 6 is not interfered with. Vhen the district sequence switchreaches position 17, the district selector and line finder restore inthe well-known manner. In position 17 of the sequence switch 300, thetiming switch is immediately buzzed into normal position over a circuitextending from battery, through the winding of magnet 625, strappedterminals 2 to 22, associated with brush 602, brush 602, interruptercontacts of magnet (S25, conductor (310 to ground at the lower leftcontact oi cam 330. Since the charging relay 396 became deenergized assoon as sequence switch 3100 passed beyond position 15, no charging pathover brush (300 is closed as the timing switch passes through positions4- to (3.

Should the called subscriber hang up at the time the timing switch (300is in position 2. relay 301 would release but the stepping path formagnet (52.3 would still be effective to advance the timing switchthrough the charging positions 8 to 0 since there would still be acircuit for magnet 625 extending from battery, winding of magnet (325,brush (301 and the No. 2 terminal of switch (300, conductor (314:, theupper contact of cam 3G4, outer left front contact of relay 302, uppercontact oi interrupter 387, conductor (331, brush (304 in position 2,conductor ($15, inner left front contact of charging relay e90, lowerleft contact of cam 39% to ground at the upper right contact of cam 350.

Ill)

In order that the control of disconnection may not be interfered withshould the calling subscriber hang up while the timing switch is passingthrough the registering positions to 6, relay 351 is reoperated. It willbe recalled that when the calling subscriber hung up, relay 351 wasreleased and relay 317 was operated to advance the sequence switch 300out of the talking position to initiate release. However, if relay 351is thus released when the timing switch is in positions 3 to 6, relay351 reoperates in a circuit from battery, through. its winding,resistance 390, conductor 632, brush 605 in positions 3 to 6, conductor630, right front contact of relay 317 to ground at the upper leftcontact of cam 336. Relay 351 in operating, at its right back contactdisconnects the left winding of relay 317 from the interrupter 391 sothat there will be no tendency for relay 317 to deenergize at eachrelease of the stepping magnet 625 of the timing switch.

Charging calls to intermediate cones of the eccchange area.

It will now be assumed that the calling subscriber has initiated a callto a less remote zone of the exchange for which but two operations ofthe message register 105 should be made for each unit period ofconversation. For such a call, relay 611 is operated as be fore, but thedistrict sequence switch is set into position 13. The circuits functionexactly the same manner as before described,-

except that during each cycle of the timing switch 600 as theconversation proceeds, no charging path to the message register 105 isclosed as the timing switch brush 606 passes through position 2. It willbe recalled that in position 20f the timing switch the circuit foroperating the message register 105 extended from ground through thewinding of register 105 over the back contact of relay 101, conductor114:, terminal 380, brush 381, conductor 616, patched through theconductors 616 and 617 to conductor 617, the lower left and upper rightcontacts of cam 306, con-ductor 618, patched through conductor 619 toconductor 619, the No. 2 terminal and brush '606, conductor 620, themiddle left front contact of charging relay 396 to battery. Sincesequence switch 300 is in position 13, however, this circuit is open atthe contacts of cam 306 and charging does not take place. Two chargesare made, however, as previously described, as the switch 600 passesthrough positions 4 and 6 during each cycle thereof. Otherwise thecircuits function as previously described.

Charging calls to nearby zones of the ecochange area.

For calls to nearby zones, for which a single reglstratlon 1s requlredfor each unit period of conversation, relay 611 1s not operated from thesender and sequence switch 300 is set into position let fortalking.Thus, during eaclrcycle of the timing switch the circuit, previouslytraced for operating the message register each time brush 606 passesthrough position 2,1s closed at contacts of cam 306. Since, however,relay 611 is not operated the paths, previously traced for operating themessage register as the timing switch passes through positions land 6,are open at the outer left front Contact of relay 611. Thus, only oneregistration for each unit period of conversation is effected Otherwisethe v circuits function as previously traced.

Free calls to certain zones ofthe eccohange I It may be desirable togive subscribers free service to certain oflices of the exchange areawhich are adjacent to the originating olfice. For such calls the relay611 is not operated and the district sequence switch is set intoposition 13 for talking. As the timing switch 600 advances during eachunit period of conversation, no paths for operating the message register105 are closed since-the path previ ously traced with the brush 606 inposition 2 is now open atcontacts of cam 306 and the paths tracedwithbrush 606 in positions 4 and 6 are open atthe outer left contact ofrelay 611.

Gross connections for changing the method of charging.

For the purpose of enabling wiring changes to be readily made wherebythe method of made for free calls. It may be desired to give fiat rateservice without consideration of the duration of the conversationalperiod on single registration calls, but retain the timing of double andtriple registration calls. To accomplish this the patching from the leftto the right side of the connectingrack 650 would be as previouslydescrihed'except' that conductor 627 would be patched to conductor 627rather than directly to conductor 626'. Thus, for calls requiring doubleor triple registrations for each unit period ofconversation, relay 611always being energized for such calls, the advance of the timing switch600 from position 7 to normal is placed under the control of the timinginterrupter 624, over a circuit extending from battery, through themagnet 625, brush 601, conductor 626, strapped to conductor 626, theright contact of relay'611, conductor 627, strapped to conductor 627,thence as previously traced to ground through contacts of theinterrupter 624. For calls requiring but a single registiming switchtherefore remains in position 7 until the termination of the call whenit is restored to normal in the manner prevlously described. A singlereglstration is thus made regardless of the length oi the conversationalperiod. Free calls are given as before described with relay 611decncrgizedand the district sequence switch 300 in position 16.

Should it be desired to limit registrations to a maximum of two, thepatching of conductor 623 to conductor 623 would be omitted and thus thethird registering impulse transmitted over brush 606 as it rotatesthrough position 6 of each cycle would not be effective.

If there are but two zones of the exchange to be considered from aregistration standpoint, then relay 611 is not necessary smcc the twotalking positions 13 and 14 of the district sequence switch aresuiiicicnt to providc the proper registration discrunmation. In thiscase conductors 612 and 613 are left unconnected at the connecting rack,conductor 619 is patched through conductor 619 to conductor 618 aspreviously described, conductor 626 is patched through conductor 626 toconductor 6:27, conductor 623 is left unconnected and conductor 622 ispatched through eonductors 622, 633, 616 and 617 to conductors 616 and617. With these connections it will be noted that all connections to thewindings and contacts of relay 611 are eliminated. Therefore, it thedistrict sequence switch 300 is set into position 14 the circuitpreviously traced for operating the register 10') will he closed overbrush 606, conductors 619, 619 and 618 during each cycle of the timingswitch and as the brush 606 passes through position 4 the messageregister will be operated asecoud time over a circuit extending frombattery, connected to brush 606, eonductors 622, 622, 633, 616 and 616,thence to the message register. Since the conductor 623 extending fromthe No. 6 terminal associated with brush 606 is unconnected, noregistration is effected as the timing switch passes through position 6.Two registrations are thus made for each unit period of conversation.With the district sequence switch 300 in position 13, the registrationpath over the No. 2 terminal of brush 606 is open at the contacts of cam306 and only one registration is effected as the timing switch movesthrough position 1 of each of its cycles.

"If there is but one charge to be made for a callfor each unit period ofconversation,

with sequence switch 300 in position 14, and

free calls with the sequence switch in posit1on13, the patching at theconnecting rack 650 would be the same as just described cxccpt thatconductor 622 would be left uuconnected.

Another type of service may be provided for where it is desired toeliminate double and triple charging but to charge certain calls on aflat rate basis or a single charge regardless oi the length of the calland other calls at a single charge rate for each unit pcriod ofconversation. This type of service may be provided by patching conductor611) through conductor 619 to conductor 6'16, patching conductor 62?through conductors 617 and 616 to conductor 618, patching conductor 626through conductor 626 to conductor 617 and leaving conductors 62:2, 623,612 and 613 unpatched. \Vith the connections made in this manner allconnections to relay 611 are open and no cfl'cctive circuits areestablished for operating the message register as the brush 606 of thetiming switch passes through positions -l and 6. 1f the districtsequence switch has been set into the talking position 14, when theswitch 606 rotates through position 2 a circuit is closed for operatingthe message register 16;) which may be traced as before to conductor616, thence over conductor 619 and 619, brush 606, conductor 620, tobattery. \Vhen the switch 600 reaches position 7, it is timed intonormal position by the interrupter 624-, over a circuit extending frombattery, winding of magnet 625, brush 601, strapped terminals 7 to 22,conductors 6:26, 626 and 61?, lower left and upper right contacts of cum306, closed in position 14:, conductors 618, 616', 617 and 627,interrupter 621, conductor 625, battery, right front contact of relay302, conductor 608 to ground at brush 602-}. Upon reaching position 1the timing switch starts on a second similar cycle. Thus, for each unitperiod of conversation, one charge is registered on the message register10:"). it. however, the sequence switch 300 is set into position 13 thecircuit last t 'aced for advancing the switch 600 from position 7 willnot be closed and therefore the switch 600 will not advance throughsuccessive cycles during the conversation and but one charge will bemade for the conversation regardless ol the length of its duration. Fromposition T the timing switch is restored in the manner previouslydescribed after the calling subscriber terminates the conversation.

Other methods of cross-connecting at the rack 650 for further types ofservice will Bug."- gcst themselves, and it is obvious that by providingadditional relays such as 611 controlled directly from the sender todesignate additional charging zones oi? the exchange area, it would bepossible to make more than three charges for each unit period ofconversation.

\Vhat is claimed is:

i. In a telephone exchange systenna calling line, a plurality of calledlines of different classes, selector switches for extending the callingline to said called lines, means for selectively operating saidswitches, means associated with one of said switches for alteringcircuits thereof in accordance with the class,

01'' the called line, a charging device for the calling line, a timingswitch, means operative upon the response of. the called subscriber toadvance said timing switch through a plurality of positions, meanscontrolled in the advance of said timing switch in accordance with thesetting off said altering means to variably operate said chargingdevice, an interrupter, and means controlled by said interrupter tothereafter advance said timing switch slowly into normal position tomeasure off a predetermined conversational period, said timing switchadvancing through siinilar cycles to repeatedly operate said chargingdevice until said connection is releasedv :2. In a telephone exchangesystem, a call ing line, a plurality of called lines of differentclasses, selector switches for extending the calling line to said calledlines, means for selectively operating said switches, means associatedwith one of said switches for altering circuits thereof in accordancewith the class of the called line, a charging device for the callingline, a timing switch, means oper-v ative upon the response of thecalled subscrib-' or to advance sald timing switch through a pluralityof positions, means controlled by.

the advance of said timing switch in accordance with the setting of saidaltering means to variably operate said charging device if said calledline is of certain classes but not to operate said charging device ifthe called line of another class, and means to thereafter advance saidtiming switch slowly into normal position to measure oil a predeterminedconversational period, said timing switch advancing through similarcycles until said connection is released.

3. In a telephone exchange system, a calling line, a plurality of calledlines oi diilerent classes, selector switches for extending the callingline to said called lines, a register sender, means for variably settingthe registers of said sender, means controlled in accordance with thesetting of said registers for selectively operating said switches, meansas sociated with one of said switches for altering circuits thereof inaccordance with the class of the called line, a charging device for thecalling line, a timing switch, means operative upon the response of thecalled subscriber to advance said timing switch through aplurality ofpositions, means controlled by said timing switch during its advance inaccordance with the setting of said altering means and the setting ofsaid registers to variably operate said call charging device, aninterrupter, and means controlled by said interrupter to thereafterslowly advance said timing switch into normal position to measure off apredetermined conversational period, said timing switch advancingthrough similar cycles. to repeatedly operate said charging device untilsaid connection is re-f leased. v

J 4. In a telephone exchange system, a calling line, a plurality ofcalled lines of diilerent classes, selector switches for extending thecalling line to said called lines, a register sender, means for variablysetting the registers of said sender, means controlled in accordancewith the setting of said registers for selectively operating saidswitches, means associated with one of said switchesi or alter 1 ingcircuits thereof in accordance with the class of the called line, acharging device for, the calling line, a timing switch, a relay asso-'ciated with said timing switch and" operative it said registers haveregistered the number of a called line ofa particular class, meansoperative upon the response of the called subscriber to advance saidtimingswitch through I a plurality ofpositions, means controlled by saidtiming switchduring its advance in ac-' cordance with the setting ofsaid altering means and the condition of said relay to variably operatesaid call charging crevice, an

interrupter, and means controlled by said interrupter to thereafterslowly advance SELlCl,

timing switch into normal position to measure oil a predeterminedconversational period, said. timing switch advancing through similarcycles to repeatedly operate said charging device until said connectionis released.

5. In a telephone exchange system, a calling line, a plurality of calledlines of ditlerent classes, selector switches for extending the callingline to said called lines, a timing switch, a call charging deviceassociated with said calling line, means operative upon the response ofthe called subscriber to advance said timing switch through apluralityoi poduring its advance to operate said charging device, meansoperat ve if has been extended to certain called lines for slowlyadvancing'said timing switch to normal to measure ofi apredeterminedconversacalled line is of anotherclass whereby said call is charged on aflat rate basis. I

6. In a telephone exchange system, a calling line, a plurality of calledlines of different classes, selector switches for extending the callingline to said called lines, a timing switch, a call charging deviceassociated with said calling line, means operative, upon the response ofthe called subscriber to advance said timing switch, a plurallty ofoperating said calling line sitions, means controlled bysaid timingswitch 11 4 paths for said charging device adapted to be closed by saidtiming switch during its advance, means for selectively rendering saidpaths effective in accordance with the class of the called line, andmeans for at will altering the control of said last means over saidoperating paths.

7. In a telephone exchange system, a calling line, a plurality 01 calledlines of dill'erent classes, selector switches for extending the callingline to said called lines, a timing switch, a call charging deviceassociated with said calling line, means operative upon the response ofthe called subscriber to advance said timing switch, a plurality ofoperating paths 'for said charging device adapted to be closed by saidtiming switch during its advance, means for selectively rendering saidpaths effective in accordance with the class of the called line, and across-connecting rack for altering the selective control of said lastmeans over said operating paths.

8. In a telephone exchange system, a calling line, a plurality of calledlines of different classes, selector switches for extending the callingline to said called lines, a timing switch, a call charging deviceassociated with said calling line, means operative upon the response ofthe called subscriber to advance said timing switch through a pluralityof positions, a plurality of operating paths for said charging deviceadapted to be closed by said timing switch during its advance, means forselectively rendering said paths efl'ective in accordance with the classof the called line, means for slowly advancing said timing switch tonormal for measuring off a predetermined conversational period, saidtiming switch then advancing through similar cycles to repeatedlyoperate said charging device until said connection is released, and acrossconnecting rack for enabling the selective control of saidoperating paths to be altered at will.

9. In a telephone exchange system, a calling line, a plurality of calledlines, of different classes, selector switches for extending the callingline to said called lines, a timing switch, a call charging deviceassociated with said calling line, means operative upon the response ofthe called subscriber to advance said timing switch through a pluralityof positions, a plurality of operating paths for said charging deviceadapted to be closed by said timing switch during its advance, means forselectively rendering said paths effective in accordance with the classof the called line, means for slowly advancing said timing switch tonormal for measuring olt a predetermined conversational period,whereupon said timing switch may be advanced through similar cycles torepeatedly operate said charging device until said connection isreleased, and a cross-connecting rack for enabling the selective controlof said charging device to be altered and the repeated advance of saidtiming switch to be nullified at will.

10. In a telephone exchange system, a calling line, a called line,selector switches for extending the calling line to said called line, atiming switch, a call charging device associated with said calling line,means operative upon the response of the called subscriber to advancesaid timing switch through a plurality of positions, means controlled bysaid timing switch during its advance to opcrate said charging device,means for thereafter slowly advancing said timing switch to normal tomeasure oil' a predetermined conversational period, whereupon saidtiming switch may be advanced through similar cycles to repeatedlyoperate said charging device until said connection is released, andmeans controlled by said timing switch for preventing the release ofsaid connection at the time said timing switch is advancing through thefirst portion of any cycle to operate said charging device.

In witness whereof, I hereunto Subscribe my name this 24 day of OctoberA. D-., 1927.

ALFRED E. HAGUE.

